#include <sstream>
#include <queue>
#include <iostream>
using namespace std;


struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode() : val(0), left(nullptr), right(nullptr) {}
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
    TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
};

/**
 * 递归实现：找到2个要交换的节点
*/
class Solution {
public:
    TreeNode* first = nullptr;
    TreeNode* second = nullptr;
    TreeNode* pre = new TreeNode(INT_MIN);

    void in_order(TreeNode* root){
        if(nullptr == root) return;
        in_order(root->left);

        // 第一个要交换的节点选择前一个节点 Ai > A(i+1), 第二个交换节点选择后一个节点 Aj > A(j+1)
        if(pre->val > root->val) {
            if(nullptr == first){
                // 首对 前 > 后的节点
                first = pre;
                second = root;
            }else{
                second = root;
            }
           
        }
        // 重要，易忘记
        pre = root;


        in_order(root->right);

    }
    void recoverTree(TreeNode* root){
        in_order(root);
        int temp = first->val;
        first->val = second->val;
        second->val = temp;
    }


};

void trimLeftTrailingSpaces(string &input) {
    input.erase(input.begin(), find_if(input.begin(), input.end(), [](int ch) {
        return !isspace(ch);
    }));
}

void trimRightTrailingSpaces(string &input) {
    input.erase(find_if(input.rbegin(), input.rend(), [](int ch) {
        return !isspace(ch);
    }).base(), input.end());
}

TreeNode* stringToTreeNode(string input) {
    trimLeftTrailingSpaces(input);
    trimRightTrailingSpaces(input);
    input = input.substr(1, input.length() - 2);
    if (!input.size()) {
        return nullptr;
    }

    string item;
    stringstream ss;
    ss.str(input);

    getline(ss, item, ',');
    TreeNode* root = new TreeNode(stoi(item));
    queue<TreeNode*> nodeQueue;
    nodeQueue.push(root);

    while (true) {
        TreeNode* node = nodeQueue.front();
        nodeQueue.pop();

        if (!getline(ss, item, ',')) {
            break;
        }

        trimLeftTrailingSpaces(item);
        if (item != "null") {
            int leftNumber = stoi(item);
            node->left = new TreeNode(leftNumber);
            nodeQueue.push(node->left);
        }

        if (!getline(ss, item, ',')) {
            break;
        }

        trimLeftTrailingSpaces(item);
        if (item != "null") {
            int rightNumber = stoi(item);
            node->right = new TreeNode(rightNumber);
            nodeQueue.push(node->right);
        }
    }
    return root;
}

int stringToInteger(string input) {
    return stoi(input);
}

string treeNodeToString(TreeNode* root) {
    if (root == nullptr) {
      return "[]";
    }

    string output = "";
    queue<TreeNode*> q;
    q.push(root);
    while(!q.empty()) {
        TreeNode* node = q.front();
        q.pop();

        if (node == nullptr) {
          output += "null, ";
          continue;
        }

        output += to_string(node->val) + ", ";
        q.push(node->left);
        q.push(node->right);
    }
    return "[" + output.substr(0, output.length() - 2) + "]";
}

int main() {
    // string line = "[1,3,null,null,2]";
    // string line = "[3,1,4,null,null,2]";
    string line;
    // getline(cin, line)
    while (getline(cin, line)) {
        TreeNode* root = stringToTreeNode(line);
        Solution slu;
        slu.recoverTree(root);

        string out = treeNodeToString(root);
        cout << out << endl;
    }
    return 0;
}